Prestressed slushing scraper with keyed bails



United States Patent [72] Inventor John M. Mckean 319 Madrid Ave., San Clemente, California 92672 21 1 Appl. No, 728,385 22 Filed May 13, 1968 [45] Patented Oct. 27, 1970 [54] PRESTRESSED SLUSHING SCRAPER WITH KEYED BAILS 17 Claims, 7 Drawing Figs.

(52] US. Cl 172/265 [51 1 E02f 3/60 [50] Field ol'Search .1 172/265, 266; 37/141(T), 135

I56] References Cited UNITED STATES PATENTS 1,397,751 11/1921 n n H 172/265 2716,824 9/1955 Francis 172/265 2,743,540 5/1956 Whislern." 172/265 2,763,074 9/1956 WhislerW, 172/266 3,164,914 1/1965 Wilson 172/265 3,340,628 9/1967 Dobbie et a1 172/265 3,392,465 7/1968 Bluemel 172/266 Primary ExaminerRobert E. Pulfrey Assistant Examiner-Alan E. Kopecki Attorney-William H Maxwell Patented Oct. 27, 1970 3,536,142

Sheet 1 of 2 INVENTOR.

Joaw /V. M: ltaw BY Patented Oct. 27, 1970 Sheet INVENTOR. I fol/1v f1 ffc/(suv 7: BY

Ann-Mr PRESTRFSSED SLUSHING SCRAPER WITH KEYED BAILS The prior art provides drag line scrapers with various modes of attachment of the bails to the bucket, for example attachments that are hooked, wedged. and bolted etc. The primary objective in addition to a properly operative scraper configuration, is the maintenance of said configuration. That is, it is most desirable to construct a scraper so that it does not become loose and inefficient, and heretofore such scrapers have become virtually ineffective for this very reason that looseness adversely affects digging angle. More particularly, scrapers of the type under consideration are pulled by means of a hoist and drag line, so as to be transported over the ground to dig and scrape and to move loose materials. It is imperative that the blade angle of the bucket be maintained for its digging function, otherwise the scraper will simply slide over a muck pile without moving a practical amount of material. Blade angle can only be held as required in a sound scraper that is not loose, and it is a primary object of this invention to eliminate looseness in a scraper. to the end that the digging angle of the blades is maintained for efficient transport of material.

The scraper art has recently turned to the so called "boltless scraper in preference to those which are bolted together. In either case, however, tightness of construction is sought for, but hard usage inevitably results in looseness. For example, bolted constructions gradually pound out and permit as much as to movement between the bails and bucket. And the same is more or less true of the more recent boltless constructions, which usually rely upon a channel in the bucket to angularly position the bail. In any event some looseness can and will develop with hard usage, it being emphasized that mining scrapers are put to abusive use which is destructive, it being common practice to employ a scraper until it is destroyed and thereby rendered inoperative. Therefore. it is an object of this invention to prolong the efiiciently elfectivc life of a scraper of the type under consideration, a bolted or boltless scraper as the case may be, by providing a "replaceable key" that eliminates any looseness that may develop.

It is still another object of this invention to advantageously employ initial lateral tightness for the purpose of maintaining vertical angularity of the bucket relative to the bails. It is the prestressed tightening of the bails when pulled laterally into assembled engagement that is advantageously employed to cooperatively combine with the presence of the keys that assure continued tightness of the assembly. The above-mentioned replaceable keys are inserted intermediate the bails and the bucket and are selectively chosen for their ability to fully occupy recesses wherein they are captured so as to spread the bails laterally. Accordingly, the bails are anchored so as to pivot together forjoinder at a drag line connection.

The various objects and features of this invention will be fully understood from the following detailed description of the typical preferred form and application thereof, throughout which description reference is made to the accompanying drawings, in which:

FIG. I is a side elevation of a slushing scraper embodying the keyed construction of the present invention.

FIG. 2 is a plan view taken as indicated by line 22 on FIG. 1.

FIG. 3 is an enlarged perspective view of the wedge block provided to join the harness bails.

FIGS. 4 and 5 are enlarged detailed sectional views taken as indicated by lines 4-4 and 5-5 on FIG. 1.

FIG. 6 is an enlarged detailed sectional view taken as indicated by line 6-6 on FIG. I, and FIG. 7 is a sectional view taken as indicated by line 7-7 on FIG. 6.

The slushing scraper of the present invention is a prestressed construction that employs selectively replaceable keys for establishing tightness of assembly throughout the lifetime of the structure. The usual mode of manufacture involves casting of the bails and bucket and it is a boltless type scraper which is particularly adaptable to the present invention, although it is to be understood that the prestressing and utility of the tight keys is applicable to any bucket and bail construction of the general type under consideration. Generally, the slushing scraper involves a bucket body A, a harness B, and a drag line connection C, it being these three elements which are combined without the use of bolts and which are locked into assembled condition by drawing together the harness B and installing the drag line connection C thereon.

The bucket body A is the main and principal element of the scraper and is the part which determines size, shape and capacity. As illustrated it is preferred that the bucket body A be reversible and it therefore involves, generally, opposite angularly related bottoms 10, a vertically disposed back II that joins the rear edge portions of the two bottoms, and opposite and substantially parallel sides I3. The bottoms 10 are substantially flat platelike elements or parts that are angularly disposed with relation to the forwardly extended disposition of the harness B. The back 11 is integrally joined to the rear edge of the bottoms I0 and to the sides 13, thereby presenting a forwardly opening bucket that serves to retain material and to cause lifting of the scraper when it becomes tilled. As shown, the sides 13 of the bucket body A may be flat vertically disposed platelike parts joined to and extending forwardly from the bottoms I0 and back 11.

The sides I3 are formed so as to capture and to hingedly receive the bails of the harness B at the exterior of the bucket body A. The harness B comprises generally a pair of like or identical balls to be later described. Said bails are separately applicable to the bucket body A and to this end the opposite sides 13 are each provided with guide means 20 and a socket 30 to receive the rear end attachment portion of each bail. The guide means 20 directs and protects the forwardly extending bail and in practice each opposite side I3 is identical with the other and comprises a vertically disposed wall of substantial thicknes with the socket 30 formed therein to open forwardly and located toward the rear and/or back 11, centrally thereof. The guide means 20 is provided to direct the forwardly extending bail and is comprised of a horizontally disposed and laterally opening channel at the outside of the bucket body. The socket 30 is of a cross'sectional extent to receive the rearmost tenninal end of the bail and is of a depth or longitudinal extent to assure capture of said end portion. The bail is normally of rectangular cross section in which case the guide means channel 20 and also the socket 30 is of like cross section, the channel having opposed shoulders 21 and 22 continuing into the socket 30 to form opposed top and bottom seats 23 and 24. Further, the channel has a flat bottom 25 substantially coextensive with the side I3 and the socket 30 has inner and outer walls 26 and 27 so as to completely embrace the end portion of the bail. As shown, the bail bears toward the bucket body A as it extends forwardly and bears away from the bucket body A at its engagement with the wall 27 of the socket 30. As later described, the bails pivotally engage into the sockets 30 and are yieldingly urged into pressured engagement with the walls 27 to bear outwardly. The guide means 20 and socket 30 place the bails immediately adjacent to the exterior face of the side [3 while the bails in effect establish a recess adapted to receive the rear end portion of the bails.

The harness Bis secondary to the main body element A and involves two like and preferably identical bails 40 that are received in the guide means 20 and sockets 30 at opposite sides 13 of the bucket body to be guided rigidly with respect to the body. As is clearly shown, the harness B extends forwardly from the bucket body A and from the sides 13, in a horizontal plane intermediate the bottoms 10. The exact angular relationship of the harness B to the bucket body A is an important factor and particularly the angular relationship of the harness to the cutting edge 25 of the bottom 10. The said cutting edge is comprised of replaceable cutters as is indicated and which are rigidly affixed to the bucket body at exactly predetermined angles, it being understood that the cutter angle is critical. The

bails 40 are received in the sockets 30 and they are embraced by the guide means through hinged engagement with the sides 13, so that when the said bails 40 are brought together with the drag line connection C a solid interlocking of the elements A and B is effected.

The balls 40 are identical, each bail being an elongate armlike structure. As is shown, the bail is of uniform rectangular cross section, having inner and outer side faces 41 and 42, and top and bottom edges 43 and 44, said faces and edges being normally related and extended substantially parallel with respect to each other. Each ball 40 is adapted to oppose the channel bottom and extends straight forward, and is bent and/or turned so as to extend to a drag point at the center of and forwardly of the bucket body. To these ends the said face 41 is directly opposed to the side l3, it being a simple matter to manufacture these features so as to have a substantially close fit.

The harness bails are hingedly related to the bucket body A and are attached to the body by providing releasable hinge points. The hinge points involve the terminal rear portion of the bails. In practice, the top and bottom edges 43 and 44 are engaged with the top and bottom seats 23 and 24, respectively. The bail edges 43 and 44 and the socket seats 23 and 24 are complementary and are wedge-shaped to have tight bearing engagement in the socket opening 20 while being free to articulate therein so as to permit swinging movement of the bail 40. To these ends the bail 40 has an outwardly faced shoulder 42' parallel to and stepped inward from its outer face 42 and disposed to engage flat on the wall 27, and it has a reclined back wall 45 disposed to clear the wall 26.

In accordance with the invention, I provide a selectively replaceable key K that is employed to prestress the assembly of bucket body A and harness B. The key K is installed at each bail 40, between the bail and the side 13 of the bucket body to hold the inner faces 41 in opposition to the channel bottoms 25. Consequently, the forwardly extending bails must be sprung together in order to engage with the drag line connection C installed. Thus, the key K in each instance has several functions; to hold the bails 40 spaced from the sides l3, to vertically position the balls, and to establish aligned pull points. Therefore, the keys K are selected for size so as to fully occu py key seats and 51 provided in the bucket body A and bails 40 respectively.

The key K can vary in form and is preferably a cylindrical pin 55 disposed on a vertical axis and having an outer wall received in semicircular seats 50 and Si in the bucket body A and harness bails 40 respectively. Each seat is concaved to receive somewhat less than half the pin diameter, and the top and bottom ends of the seats are frustoconical in order to engageahly receive complementary conical ends 58 and 59 on the pins. The two seats 50 and 51 are registered half-shell recesses in parts that are juxtaposed and held in spaced relation by the key pin 55 embraced therein and thereby captured in working position. The pin size. diameter and length is selected for maintaining the optimum spaced relationship hereinabove referred to. In practice, a pin of oversize can be selected and dressed down in dimension, as by means of grinding, so as to fit tightly while spacing the harness bail from the bottom 25 said optimum spaced distance substantially as shown.

Having manipulated the principal elements A and B into an assembly of parts as shown and above described, the foremost end portions of the balls are brought together by the drag line connection C, thereby conditioning the assembly for use. To this end the drag line connection C is provided and which stresses the bails 40 by bringing them together at the apex of the slushing scraper assembly. in accordance with the invention it is this drag line connection C that holds the sloshing scraper in its assembled working condition, with the foremost extended portions of the bails 40 drawn inwardly together and with the drag line L coupled to the assembly. Accordingly, the invention involves a lock collar 65 and a wedge block 70 which has a cable coupler incorporated therein. The lock collar 65 embraces the forwardly extended portions 60 of the two bails, while the wedge block 70 occupies a breech or otherwise open space intermediate the portions 60 to force said portions into engaged embracement with the surrounding collar.

During assembly of the harness B to the bucket body A, the bails 40 are sprung inwardly or together for the reception of the lock collar thereover. Therefore, the securement means that retains the lock collar 65 in working position on the harness involves opposed shoulders 61 and 62 disposed normal to and projecting outwardly from the outer side face 42 of the two bails 40, respectively. The said bail portions 60 extend parallel in spaced relationship to each other, when the parts are in finally assembled position, and the shoulders 61 and 62 are of substantial height and so spaced as to oppose opposite front and back ends of the collar to be described. Further, the inside face 41 of the said parallel portions 60 are modified so as to be rearwardly divergent at 63 in their establishment of the above referred to breech therebetween. It is this divergent and/or tapered breech opening which receives the wedge block 70.

The lock collar 65 is provided for the hoop-stressed encompassing embraeement of the two forwardly extending bail end portions 60. In practice the composite cross section of the two bails with a normal breech therebetween is that of a rectangle, and consequently the lock collar 65 is of rectangular crosssectional configuration. As shown, the lock collar 65 is an open ended box section with flat vertically disposed cheek plates 66 to engage flatly against the outer side face 42 inter mediate the shoulders 61 and 62, and it has flat horizontally disposed header plates 67 to engage flatly with the top and bottom edges 43 and 44. The lock collar 65, which is essentially square, is placed over the bail end portions 60 as shown, whereupon the wedge block 70 is put into place, loosely, to occupy the breech between the inclined faces at 63.

The wedge block 70 that is simply put into place as above described is essentially a trapezoidal solid, having flat vertically disposed and rearwardly divergent cam faces 73 to engage flatly with the opposite cheek plates 66, and having flat horizontally disposed and parallel top and bottom faces 74 and 75 to slideably enter between the header plates 67. lt will be apparent that the wedge block 70 as it is shown and described will enter into position in the breech opening between the bails 40, to forcibly separate the end portions 60 and to press them into tight engagement with the cheeks 67 of the lock wedge block 70 is moved as by pulling it forwardly with the cable coupled thereto as will now be described.

The tapered coupling structure is provided in accordance with the invention, to cause the assembly to remain intact directly as a result of the connection thereto of the drag line L and without the aid of intervening means. The coupling of drag line L to the assembled slushing scraper is established in the configuration of the wedge block 70. As shown, the wedge block is provided with a cable receiving channel 77 that ex tends around the rear end 7] and opens at the top and bottom of the wedge block at the front end 72 thereof. Specifically, the channel 77 is coextensive of and extends continuously along the top 74, end 71 and bottom 75, there being rounded interconnection of the channeled portions that lie in a common plane. Further, the channel 77 is sufiiciently deep so as to accommodate the complete diameter of the drag line cable, and at the end 71 the depth is so increased as to prevent bruising of the cable when sledges or the like are used to drive the wedge block 70 into place. It is a simple matter to thread the drag line cable through the channel and to tie the loose end as indicated.

From the foregoing it will be seen that there is a cooperative relationship in the combination of the slushing scraper bucket body A, harness B and keys K, wherein advantage is gained in the bringing of the balls together in order to prestress the assembly. The bucket and harness construction can vary greatly, bolted or otherwise fashioned substantially as hereinabove described, and it is the unique keys K that are sized and installed as described and which assure a tight scraper construction. A feature of the invention is the plurality of functions that are performed by the keys K, and namely the general establishment of an immovable pull point. Specifically, the keys K function to provide generously adequate sheer lines extending the full lengths of the pins 55, to be installed in an oversized configuration thereby functioning to provide tightness in the above-mentioned sheer line and to establish the stress whereby the bails 40 are yieldingly clamped toward the sides 13 of the bucket body A, and to simultaneously assure clearance for the juxtapositioning of the bails 40 from the channel bottoms 25 in order to establish clearance for sub stantial wearing of the pins 55. Therefore, the keys K in the form of the pins 55 are permitted to wear during continued use of the slushing scraper assembly remains tight, and when looseness does begin to occur the keys K in the form of enlarged pins 55 are replaced, thereby putting the slushing scraper assembly into new condition with respect to tightness.

Having described only a typical preferred form and application of my invention, 1 do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any modifications or variations that may appear to those skilled in the art.

lclaim:

1. In a slushing scraper of the character described wherein the principal elements are rigidly assembled: a bucket body having a transverse bottom with a forwardly disposed cutting edge therealong and having opposite substantially parallel sides extending forwardly from the bottom, and each side having a forwardly opening socket and a recess spaced forwardly therefrom; a harness comprised of a pair of like bails and each hinged on a vertical axis to a side of the bucket body by means of its rearmost end portion projecting into and occupying the socket in each side respectively, and each bail having a recess spaced forwardly from the socket to oppose and complement the first mentioned recess in each side of the bucket body respectively; a key at each bail and occupying the complementary recesses respectively and engaging the sides of the bucket body and the bails to hold the sides and the bails in juxtaposed spaced relation at said keys respectively; and means to draw the foremost ends of the bails together at a drag line connection, thereby swinging the bails on said vertical axes and em gaging the bails with said keys and the keys with the opposite sides of the bucket body respectively to pressure the harness into assembled engagement with the bucket body.

2. The slushing scraper as set forth in claim I and wherein the complementary recesses are semicircular and the keys are each a cylindrical pin seated in the opposed recesses respec tively.

3. The slushing scraper as set forth in claim 1 and wherein the complementary recesses are semicircular with frustoconical ends and the keys are each a cylindrical pin with conical ends seated in the recesses respectively.

4. The slushing scraper as set forth in claim 1 and wherein the complementary recesses are vertically disposed and semicircular and the keys are each a cylindrical pin and each on a vertical axis seated in the opposed recesses respectively.

5. The slushing scraper as set forth in claim I and wherein the complementary recesses are vertically disposed and semicircular with frustoconical ends and the keys are each a cylindrical pin with conical ends and each seated on a vertical axis in the recesses respectively.

6. The slushing scraper as set forth in claim 1 and wherein the opposite sides of the bucket body each has a horizontally disposed laterally open channel opening forwardly and closed at its rear by said socket. and wherein the bails are protectively carried in said channels respectively.

7. The slushing scraper as set forth in claim 1 and wherein the sockets at the opposite sides of the bucket body are complementary in shape to the rear end portions of the balls and have inwardly faced seats to engage the outwardly faced sides of the bails at the end portions thereof respectively.

8. In a boltless slushing scraper wherein the principal elements are prestressed as a rigid assembly: a bucket body having a transverse bottom with a forwardly disposed cutting edge therealong and having opposite substantially parallel sides extending forwardly from the bottom, and each side having a forwardly opening socket and a recess spaced forwardly therefrom; a harness comprised of a pair of like bails and each hinged on a vertical axis to a side of the bucket body by means of its rearmost end portion projecting into and occupying the socket in the side respectively, and each bail having a recess spaced forwardly from the socket to oppose and complement the first mentioned recess in each side of the bucket body; a key at each bail and occupying the complementary recesses respectively and engaging the sides of the bucket body and the bails to hold the sides and the bails in juxtapositioned spaced relation at said keys respectively, and a drag line cable con nection to releasably draw the foremost ends of the bails together and comprising, opposed and rearwardly convergent faces at the foremost ends of the bails respectively, an encompassing lock collar embraceably surrounding the foremost ends of the bails, and a wedge block having rearwardly divergent faces and interposed between the foremost ends of the bails to flatly engage the first mentioned convergent faces, there being a forwardly opening channel centrally of the wedge block to receive a rear end portion of a drag line cable, said assembly being accomplished by bringing the bails together against said keys and embraced within said lock collar with the wedge block therebetween, and with the end portion of the drag line cable protectively extended through the channel and tied ahead of the wedge block so as to pull the wedge block forwardly relative to the harness bails when the cable is taut.

9. The slushing scraper as set forth in claim 8 and wherein the complementary recesses are semicircular and the keys are each a cylindrical pin seated in the opposed recesses respectively.

10. The slushing scraper as set forth in claim 8 and wherein the complementary recesses are semicircular with frustoconical ends and the keys are each a cylindrical pin with conical ends seated in the recesses respectively.

11. The slushing scraper as set forth in claim 8 and wherein the complementary recesses are vertically disposed and semicircular and the keys are each a cylindrical pin and each on a vertical axis seated in the opposed recesses respectively.

12. The slushing scraper as set forth in claim 8 and wherein the complementary recesses are vertically disposed and semicircular with frustoconical ends and the keys are each a cylindrical pin with conical ends and each seated on a vertical axis in the recesses respectively.

13. The slushing scraper as set forth in claim 8 and wherein the opposite sides of the bucket body each has a horizontally disposed laterally open channel opening forwardly and closed at its rear by said socket, and wherein the bails are protectively carried in said channels respectively.

14. The slushing scraper as set forth in claim 8 and wherein the sockets at the opposite sides of the bucket body are complementary in shape to the rear end portions of the bails and have inwardly faced seats to engage the outwardly faced sides of the balls at the end portions thereof respectively.

15. A slushing scraper including, a bucket body, a harness with a pair of forwardly extending bails carrying said bucket body, and a drag line cable connection to releasably hold the foremost ends of the bails together and comprising, opposed and rearwardly divergent faces at the foremost ends of the bails respectively, an encompassing lock collar embraceably surrounding the foremost ends of the bails, and a wedge block having rearwardly divergent faces and interposed between the foremost ends of the bails to flatly engage the first mentioned divergent faces, there being a forwardly opening channel centrally of the wedge block to protectively receive a rear end portion of a drag line cable, said channel extending coextensive along opposite sides of the wedge block, said assembly being accomplished by bringing the bails together and embraced within the said lock collar with the wedge block therebetween, and with the end portion of the drag line cable extended rearwardly through the channel at one side of the wedge block and forwardly through the channel at the other side of the wedge block and tied ahead of the wedge block so as to pull the wedge block forwardly relative to the harness bails when the cable is taut.

16, The slushing scraper and its drag line cable connection as set forth in claim 15. wherein the said channel extends continuously across the rear of said wedge block between the channels on the sides, and wherein the joinder of the channel portions is rounded.

17. The slushing scraper and its drag line cable connection as set forth in claim 15, wherein the said channel extends continuously across the rear of said wedge block at a depth substantially in excess of the cable diameter and between the channels in the sides, and wherein the joinder of the channel portions is rounded. 

